title: Enhanced anti-diastereo- and enantioselectivity in alcohol-mediated carbonyl crotylation using an isolable single component iridium catalyst.
abstract: The cyclometalated iridium complex (S)-I derived from [Ir(cod)Cl](2), 4-cyano-3-nitrobenzoic acid, allyl acetate, and (S)-SEGPHOS is conveniently isolated by precipitation or through conventional silica gel flash chromatography. This single-component precatalyst allows alcohol mediated carbonyl crotylations to be performed at significantly lower temperature, resulting in enhanced levels of anti-diastereo- and enantioselectivity. Most significantly, the chromatographically isolated precatalyst (S)-I enables carbonyl crotylations that are not possible under previously reported conditions involving in situ generation of (S)-I.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Gao
authors.forename: Ian A
authors.initials: IA
authors.lastname: Townsend
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Krische
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000438:Alcohols / Q000737:chemistry*; D000447:Aldehydes / Q000737:chemistry*; D000498:Allyl Compounds / Q000737:chemistry*; D002384:Catalysis; D002850:Chromatography, Gel; D007495:Iridium / Q000737:chemistry*; D015394:Molecular Structure; D009570:Nitriles / Q000737:chemistry*; D009579:Nitrobenzoates / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: C561163:4-cyano-3-nitrobenzoic acid; D000085:Acetates; D000438:Alcohols; D000447:Aldehydes; D000498:Allyl Compounds; D009570:Nitriles; D009579:Nitrobenzoates; D009942:Organometallic Compounds; D007495:Iridium; C498551:allyl acetate